llvm-6502/lib/CodeGen/AsmPrinter/Win64Exception.cpp
Saleem Abdulrasool 622520e70f MC: rename EmitWin64EH routines
Rename the routines to reflect the reality that they are more related to call
frame information than to Win64 EH. Although EH is implemented in an intertwined
manner by augmenting with an exception handler and an associated parameter, the
majority of these routines emit information required to unwind the frames. This
also helps identify that these routines are generic for most windows platforms
(they apply equally to nearly all architectures except x86) although the
encoding of the information is architecture dependent.

Unwinding data is emitted via EmitWinCFI* and exception handling information via
EmitWinEH*.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211994 91177308-0d34-0410-b5e6-96231b3b80d8
2014-06-29 01:52:01 +00:00

108 lines
3.6 KiB
C++

//===-- CodeGen/AsmPrinter/Win64Exception.cpp - Dwarf Exception Impl ------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains support for writing Win64 exception info into asm files.
//
//===----------------------------------------------------------------------===//
#include "DwarfException.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/Twine.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Mangler.h"
#include "llvm/IR/Module.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/Dwarf.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/FormattedStream.h"
#include "llvm/Target/TargetFrameLowering.h"
#include "llvm/Target/TargetLoweringObjectFile.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Target/TargetRegisterInfo.h"
using namespace llvm;
Win64Exception::Win64Exception(AsmPrinter *A)
: EHStreamer(A), shouldEmitPersonality(false), shouldEmitLSDA(false),
shouldEmitMoves(false) {}
Win64Exception::~Win64Exception() {}
/// endModule - Emit all exception information that should come after the
/// content.
void Win64Exception::endModule() {
}
/// beginFunction - Gather pre-function exception information. Assumes it's
/// being emitted immediately after the function entry point.
void Win64Exception::beginFunction(const MachineFunction *MF) {
shouldEmitMoves = shouldEmitPersonality = shouldEmitLSDA = false;
// If any landing pads survive, we need an EH table.
bool hasLandingPads = !MMI->getLandingPads().empty();
shouldEmitMoves = Asm->needsSEHMoves();
const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
unsigned PerEncoding = TLOF.getPersonalityEncoding();
const Function *Per = MMI->getPersonalities()[MMI->getPersonalityIndex()];
shouldEmitPersonality = hasLandingPads &&
PerEncoding != dwarf::DW_EH_PE_omit && Per;
unsigned LSDAEncoding = TLOF.getLSDAEncoding();
shouldEmitLSDA = shouldEmitPersonality &&
LSDAEncoding != dwarf::DW_EH_PE_omit;
if (!shouldEmitPersonality && !shouldEmitMoves)
return;
Asm->OutStreamer.EmitWinCFIStartProc(Asm->CurrentFnSym);
if (!shouldEmitPersonality)
return;
const MCSymbol *PersHandlerSym =
TLOF.getCFIPersonalitySymbol(Per, *Asm->Mang, Asm->TM, MMI);
Asm->OutStreamer.EmitWinEHHandler(PersHandlerSym, true, true);
Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_begin",
Asm->getFunctionNumber()));
}
/// endFunction - Gather and emit post-function exception information.
///
void Win64Exception::endFunction(const MachineFunction *) {
if (!shouldEmitPersonality && !shouldEmitMoves)
return;
Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("eh_func_end",
Asm->getFunctionNumber()));
// Map all labels and get rid of any dead landing pads.
MMI->TidyLandingPads();
if (shouldEmitPersonality) {
Asm->OutStreamer.PushSection();
Asm->OutStreamer.EmitWinEHHandlerData();
emitExceptionTable();
Asm->OutStreamer.PopSection();
}
Asm->OutStreamer.EmitWinCFIEndProc();
}